Closes#294
This adds import for Safari/webkit profiler. Well, for Safari 13.1 for sure, I haven't done any work to check if there's been changes to the syntax.
It seems to work OK, and is already a huge improvement over profiling in Safari (which doesn't even have a flame graph, let alone something like left heavy). Sadly, the sampler resolution is only 1kHz, which is not super useful for a lot of profiling work. I made a ticket on webkit bug tracker to ask for 10kHz/configurable sampling rate: https://bugs.webkit.org/show_bug.cgi?id=214866
Another thing that's missing is that I cut out all the idle time. We could also insert layout/paint samples into the timeline by parsing `events`. But I'll leave that for another time.
<img width="1280" alt="Captura de pantalla 2020-07-28 a las 11 02 06" src="https://user-images.githubusercontent.com/183747/88643560-20c16700-d0c2-11ea-9c73-d9159e68fab9.png">
Jamie Wong
f3a1c09c9b
